Valve stem



M. A. SOROKIN VALVE -STEM oct. 2s, 1941.

' Filed Feb. 8, 1939` Amm? *Suma/wwf,

Sfr/tommy Patented Oct. 28, 1.941k

Michael A.l sorokimMilforrf, Conn., assigner to Jenkins Bros., Bridgeport, Conn., a corporationv j of New Jersey i Appueauun February s, 1939, yserial No. 255,322

z remise-4436)"L This invention relates vto valve stems and par-v ticularly to rubber lvalve stems. More particularly the invention relates to rubber valve stems vdesigned for use in -connection with the tires o heavy trucks and buses and-the like. A particular advantage of the new valve stem is real-v ized when it is applied to the inner one of the tires of a double-tired wheel. y

In the case of the double-tired wheel the rimy which carries the inner one of the two tires ordinarily -surrounds a brake drum `with very little clearance between the two; In order that this tire may be serviced,it has been the custom heretofore to provide it with an elongated, bent,y metal' stem `passing between the rim and the drum and out between the spokes so as to be accessible for the application of an inilating chuck or a cap. In use, this metal stem absorbs heat Figure 3 is an axial section of thecentral poration' oi" the stemof'Figure-.2,` considerably enlarsed, and l Figure 4 1s a'sectionjnke .that of riigure 3 but;

from the frequently very highly heated drum and carries this heat to the valve provisionsso that the rubber portions 'of the latter rapidly deteriorate and'must be replaced. Furthermore, in

The tip portion 8 comprises a substantially cy` 'the case of puncture, thetube frequently is tom from the metal stem which cannot follow the` tube if there is rel/ative rotation between it and the wheel rim. f

With the valve/provisions heretofore'in common useit has been considered necessary to provide a secondary seal in the form of a capy threadable on the end of the metal stern, and the long, bent metal stem has been necessary in order to render the end of the stem accessible so that a' cap may be threaded thereon, as above men-f tioned. Even with a very short, straight, metal f stem, the clearance between the drum and surrounding rim is ordinarily such ,that it would be impossible to thread a cap on the stem or remove'it.

It is a principal object of the present inventiony to provide a straight, short stem accessible tov an infiating chuck, and of such construction that I the cap becomes unnecessary. AAnother object of the invention is to provide a stem so` proportioned as to b'e enabled to withdraw readily through the rim opening so as to avoid damage showing'a-moditied form of internal construction. Y l

cReferring iirstto Figures Zand 3 of the drawing,y the illustrated stexncomprises a base flap I, and a shaft or body ,portiongenerally indis ycated at 6 which rises 'fromthe flap and is ordinarily molded lintegrally therewith.r If .theushaft is formed integrally with thetube, the flap, as such, is omitted; As here shownggthe vilap is contemplated as Abeing of circular form vwith its Vmargins beveled toa feather edge, and Athe shaft 8 rises from the'center ofJthe flap.

The shaft -6 comprises asubstantially cylindrical`or somewhat upwardlyftaperedportion 1 immediately adjacent theiiap, the portion l being mergedy into a reduced tip portion 8 of circular section through "a rounded shoulder 9,.

lindrical portionI I0, immediately adjacent the shoulder 9, and a slightly-conical or tapered extremity I-I. Y Molded inthe stem is an insert generally ini dcated at ,.I2, Figurev3. As shown in the ligure,

the insert isv made up of a pair of telescopedr tl'ieflatter being outwardly ilanged atk I5, and the lower edge ofthe former being outwardly flanged at I8 and'bent-or spun: around the flange I5 Afso` as .to embracethe latter and securely hold the shellstogether.y vThe shell I3 has a lower cylindrical -portion I1 which through a shoulder It'y is4 joined witha reduced upper portion ,I9 which. conforms `internally substantially to the outward shape of the Vtip liso1 that a chamber is provided whicnfha's lowerrsubstantially cylindrical walls 20- and tapering upper4 walls 2|,

- which latter define a slightly constricted circuto the tube when a puncture occurs in use. These purposes are achieved in the use of a stem such as is shown by way of example in the accompanyingA drawing, to which reference will now be made in explaining the invention.

In the drawing:

Figure 1 is an axial section of a double wheel equipped with stems according to the invention;

Figure 2 is an elevation Vof a stem such as is showninFlgure 1; I

lar end opening.- 22. The shell Ilvis shaped to t snugly within theylower portion of shell I3 and against the shoulder of the latter, having alsov an inwardly extending iiange 23 which defines a circularopening 24 on the axis of the In the molding operation the insert I2 visembedded in therubber composition so as to be completely surrounded Vby the latter '-except, ordinarily, for the top edge of the insert at thev opening. Furthermore, the'insert is completely lined internallywith the,` rubber composition up to being left internally exposed. The rubber lining .light metal shells I3 and Il, the lower edge of ythe flange 23, `the Vmetal of the tip portion I9.

defines an axial passage comprising a lower cylindrical portion 25 which through a conical portion 25 is merged into a reduced cylindrical portion 21 of the same diameter as, and coaxial with, the opening 24. When the conical portion 26 meets the cylindrical portion 21, there is formed a sharp edge 29 designed to serve as a valve seat.

Cooperating with the seat 29 is a conical valve body 29 whose angle to its axis is considerably sharper than the angle of the conical passage portion 26 so that an initial line contact, which widens under the spring and air pressure in use,

is afforded between the valve body antiY the seat.

A pin 30 secured to valve body 29 extends upwardly into the tip portion and has secured to its upper end a circular head 3| which substantially fills the end opening 22 when body 291s seated and may nonmally project slightly outwardly as shown. A compression spring 32 is interposed between vhead 3| and flange 23 and i. normally holds body 29 yieldingly seated. The

head is freely axially movable atall times in opening 22 so .that it can never interfere with the full seating of body 29. Normally the head serves as a closure to keep foreign matter from the tip chamber. During inflation it moves inwardly of the chamber to permit the passage of air to the tube, the movement being caused either by a trip pin in the ,chuck or by air pressure. It will be seen from Figure '3 that the loweroutwardly anged end of the insert is completely embedded in the flap and serves as an effective anchoring provision. In the preferred relation shown, the flanged lower end is completely within the, projection of cylindrical portion 1 so that the' flexibility of the flap is not substantially impaired and it may conform freely to a tube to which it is subsequently vulcanized.

Figure 2 shows the new stem in substantially the actual size which has been successfully used,

and theproportion of parts shown in this figure are preferred, although they may be varied without necessarily departing from the invention. As shown, the tip portion 9 is oi' suitable diameter, for example about nine-thirty-seconds of an inch, and of suitable length, for example about three-eighths of an inch, to be received in an inflating chuck. The length of the tip portion is preferably not substantially greater than that necessary for operative engagement in the chuck. The remainder of the shaft 6, including cylindrical `portion 1 and shoulder 9, is about twice the length of the tip portion and is of about twice the diameter of the latter. The cylindrical portion [preferably does not greatly exceed in length the thickness of a wheel rim at the rim opening.

space and having a head 42 provided with a side opening, as shown. Rim 36 carries a casing 43, inner tube 44, and valve stem 45 exactly as rim 35.

s shown in Figure l, the projection of the valve stems depends only on the thickness of the rims, which are of metal and may be of a thickness up to one-quarter of an inch or more. In such practice, the lower portion of the shaft may be made even shorter than shown. However, it is not unusual practice to provide a flap or liner between the inner tube and the rim, and this flap often has a thickness up to one-quarter of an inch or more-which must be traversed by the valve stem in addition to the rim. With such a flap, the projection of the stem would be substantially reduced as compared to that shown in Figure 1. Where the annular space is extremely restricted, a further spacing member in the form of a disc of desired thickness provided with an opening for thev stem may be used. In other words, the rim structure as a whole may include several layers which will be traversed by the valve stem, as will be hereinafter further discussed. The proportions shown in Figure 2 are such that the stem is adaptable to the various usages. f

Furthermore, due to the relatively large diameter of the shaftportion 1 as compared to the tip portion I0, and due to the fact that the portion 1 projects little, if any, beyond the rim, ready withdrawability is achieved so that in case of relative 'movement between the tube and rim, the stem can follow the tube without being torn from the latter. f

The insert I2 of Figure 3 is of preferred construction, being relatively thick-walled below the valve seat so as to effectively prevent ballooning under high pressures. Furthermore, the insert is conveniently made from parts of uniform wall thickness. In Figure 4 the insert 46 is of integral construction and includes a relatively thickwalled lower portion 41 and a relatively thinwalled tip portion 48 separated by an integral ange 49 which, as before, backs the seat inA conjunction with the insert shoulder and serves as a spring seat. In Figure 4 I have indicated, in dotted lines and in part, a wheel rim at 50, a ap or liner'at 5|, and a washer-like spacing member at 52. Only the tip portion of the stern projects through the rim opening. With the spacing With a stem of the size shown in Figure 2 and f with a metal rim one quarter of an inch thick, the major length of the cylindrical portion 1 would be in the rim opening. i

In Figure 1 a wheel generally indicated at 33 has the spokes 34, the two rims 3.", and 36 and the brake drum 31, there being a restricted annular space between the drurm 31 and rim 35.

Rim 35 carries a casing 38 and an inner tube 39 which latter is provided with a valve stem 43, suchas heretofore described, the valve stem projecting through a rim opening slightly into the space between the rim and drum. This projection may be no more than sufllcient to aord operative engagement by an inilating chuck, such as indicated at 4I, the chuck being introduced between the wheel spokes and into the annular member omitted the combined thickness of the rim and flap would be about the same as the length of the cylindrical base portion of the flap, so that the shoulder, as well as the tip portion. would project. 'Ihe relatively light metal parts do not conduct heat unduly so that the valve seat is enabled to stand up during a long period of use.y

'I'he rubber of the stem is yieldable throughout and may be of the same composition as that employed in rubber valve stems heretofore in use.

In using such terms as upper and 1ower" herein, reference is had to the stems in the position shown in Figures 2 to 4 and the terms are iised merely as a matter of convenient descrip- It will be noted that the flap 5 of Figure 2 is shaped for application to the outside of the tube. With a ap for application to the inside of a tube it would be necessary to lengthen the cylindrical portion 1 by the thickness of the tube in order to retain the preferred proportions which have been discussed.

It will be understood that variations in detail are possible from the disclosure herein without departure from 'the invention,` and accordingly, I do not limit myself to matters of form and arrangement except as in the following claims. In these claims the term rubber is intended to include any rubber-like composition, natural or artificial.

I claim: 1. A valve stem comprising a rubber flap and a rubber shaft integral with said flap, a tubular insert coaxially incorporated in and extending through said shaft and into said flap, said shaft extending from the ilap and terminating'in a tapering annular shoulder; said insert having a tip lportion projecting beyond said shoulder, a base portion within the base portion of the shaft and of enlarged cross-section as compared to the tip portion, and an annular shoulder adjacent 4and within the shaft shoulder joining the tip and base portions of the insert, the insert being flanged within the ap and the base and shoulder portions of the insert being constituted by telescoped portions; there being a passage extending throughout said insert and through said nap.

2. A valve stem including a tubular insert having upper and lower portions, said upper portion being of mailer cross section than said lower portionand said portions being joined by a tapered shoulder, said insert also including an inwardly directed shoulder in adiacency to the upper extremity-of said tapered shoulder and adapted to provide an abutment for a spring, a rubber body portion in which said lower portion of said insert and said tapered shoulder are embedded whereby said rubber body portion includes inner and outer sections of which the outer has a tapered shoulder embracing the tapered shoulder of the insert, said inner section extending within said insert throughout the length of the lower portion of said insert and crossing the tapered shoulder of the insert but terminating at said inwardly directed shoulder to constitute a rubber valve seat that is backed by the insert shoulders, and a rubber ilap with which said sections are integrally Joined,

said insert terminating at its lower end within said flap, the length of the sterny portion beyond the shoulder of said outer section being on the orderofone third of that of the stem from its tip to said flap and the length of said outer section between its shoulder and said flap being on the order of the thickness of a wheel rim structure. l

MICHAEL A. sonoKiN. 

